When I Turn Jet Black, and You Show Off Your Light
by BulletBlaze
Summary: When Derek comes to Stiles, trembling and crying, and tells him some terrifying news, Stiles vows to do whatever it takes to save Derek from a life he doesn't want. -Or- The Angels and Demons AU with a slight twist.


**Rated teen+ for some language**

 **Title and lyrics from 'Boats and Birds' by Gregory and the Hawk**

 **Enjoy!**

 _ **If you'll be my star, I'll be your sky**_

 _ **You can hide underneath me and come out at night**_

 _ **When I turn jet black, and you show off your light**_

 _ **I live to let you shine**_

 _ **I live to let you shine**_

For his whole life- all 80 years, so far- Stiles had known Derek.

Their mothers had always been the best of friends, despite the horrible insults and threats they frequently received because of it. And because of their close relationship, Derek and Stiles had grown up around each other. By the time they were only 16, they were so used to being around each other that they would often cry if they were apart for too long.

As the two eventually grew into adolescence together, they began to discover just why their parents always told them to keep their friendship as subtle as possible. As Stiles found out in his seventh year of high school, demons didn't appreciate it when angels hung around their kind too much, and they certainly didn't take kindly to a 'weak-winged bitch' calling them out on their unfair treatment of other classmates.

That was the day they broke Stiles' wings.

Held him down and snapped them both right in half.

Stiles never knew one body could hold so much pain in one moment, or one mind could hold so much anguish in another, when they told him they would never fully heal.

He would never be able to fly again. He would never be able to become a Guide of the dead, like his mother had been, or a Guardian of the living, like his father, or a Healer of the weak, like Scott's mom.

He'd be stuck in the sky, forever.

After all, leaving the clouds for Earth without wings was suicide. You'd crash and burn into nothingness before even reaching the Stratosphere.

From then on, Stiles had to be flown to school by one of the Secondary Guardians and only got to see Derek, who was completely and utterly horrified by what had happened, there and when his friend shadow jumped, which wasn't often because it made him weak.

Needless to say, Stiles wasn't in a very good place.

He missed his freedom, he missed his dreams, he missed the feeling of soaring through the air on a cool, humid morning, bursting through clouds and disrupting the fog and flying down to Derek, landing to the sight of his pleased smile and a welcoming hug…

He missed everything. But he missed Derek the most.

Ever since the incident, Derek had become much more aware of the issues between angels and demons. The Hale's were powerful and influential demons. But they were also nice, and fair, and accepting. It was because of them that his assailants got put in the pit for the next hundred years. Stiles would've liked longer, but he supposed a quarter of their lives was decent enough.

Talia had even told Stiles that Mr. Hale would be attending to them personally.

Eric Hale. The Beast of Hell. The most ruthless torturer in all of the pit.

Also Derek's father.

It warmed Stiles, even if just slightly, to know that Talia took his attack so personally.

But it did nothing for his wings, his freedom, his _life._ His rage.

It was a few long years later, so long they felt like _decades,_ when Derek appeared out of the shadow cast by Stiles' circle of pillars, made for precisely that purpose, trembling and ghastly pale. Stiles barely got him to his bathroom before he was convulsing and vomiting into the toilet. Derek continued to throw up for another few minutes until he was heaving only the lining of his stomach, and then nothing.

Later, when Stiles led Derek over to his bed, he asked the demon what was wrong.

"My dad talked to me today," he started quietly.

Stiles didn't push, letting Derek take the time he needed to collect himself.

"He told me… I'm taking his place. Once I'm done with my training in a few decades. I'm going to be the next Beast."

Stiles sucked in a sharp gasp, a hand coming up to cover his mouth as his eyes widened.

Reaching a hand out to grasp Derek's shoulder, Stiles whispered, "Derek… Shit, can't someone else do it? Laura, or Cora, why can't they do it?!"

Derek looked almost numb as he shook his head. "Laura's been meant to take over for Mom since she was born. And Cora's been training under Peter to become a crossroads demon her whole life."

"Well what about you! Don't they care about what you want?!" Stiles shouted, angry for Derek and the unwanted life he was being subjected to.

"Stiles…" Derek breathed. "I haven't been training for anything specific. I don't… I don't have a dream. None of my options ever sounded right." Derek scoffed bitterly, but it came out more like a cry. "I don't want to spend my life hurting people, or tricking people, or sealing people's deaths. I don't want it, Stiles, I don't want it! I don't want to do this, I don't want to _be this!"_

Derek's eyes overflowed with tears as a strangled scream ripped from his throat, hands pulling at his hair and his face screwing up tightly. His anguished cry abruptly cut off and he started gasping for air, clawing at his neck and chest when it just wouldn't come.

Cursing under his breath, Stiles moved behind Derek and pulled the boy to his chest. His arms wrapped around Derek's waist, pulling Derek's back flush against himself so that he could feel each of Stiles' deep breaths.

"C'mon, Derek, breathe with me. You can do it, I know you can. You can do anything, Der, just copy me, okay? I promise it'll all be okay, alright? I swear to you, we'll figure this out, you just have to _breathe."_

It took nearly ten minutes to get Derek completely calmed down, after which he collapsed against Stiles, body gone limp with exhausted sleep.

Stiles moved his friend until he was laying comfortably on the bed, wrapped in soft blankets and safe from the worlds, even if just for a few hours.

Stiles, on the other hand, had something he needed to do.

 _ **But you can skyrocket away from me**_

 _ **And never come back if you find another galaxy**_

Stiles convinced Isaac to fly him down to Earth, saying that it was important and that he could come pick him back up in an hour.

That's how the angel found himself standing at a dark, gravel intersection in the back roads of some small town in Europe, spilling a few drops of blood into the dusty rocks and chanting a few phrases of Latin.

The light of the moon faded until Stiles could barely see. A light breeze whispered through the air around him, bringing with it a bone-deep chill and the smell of burnt timber.

"Stiles. It's lovely to see you, though I must say, I am a bit surprised."

Turning around to face the smooth voice, Stiles came face-to-face with the King of the Crossroads himself.

"Peter. I want to make a deal."

The man's eyes widened in genuine surprise. "Oh, really? Well, that is interesting. What could a little angel such as yourself want from a big bad demon such as I? Power, your mother, your wings? Do you even know what any of that costs?"

"No," Stiles said firmly, not letting his mind linger on the thought of having his mother back, or his wings healed. That wasn't what he was there for. "I want to make a trade of sorts."

"Well, that is typically how this works. I give you something, you give me something of equal value-"

"A different kind of trade," Stiles interrupted. "I… I want…"

"Any day now, kid," Peter sighed in annoyance.

Stiles stole himself, took a deep breath, and stated, "I want you to make Derek an angel, and I'll take his place as a demon."

Peter stared at the boy in front of him in shock for a moment. "That… was honestly not what I was expecting. Now, why would you want that?"

"Derek doesn't want to become the Beast," Stiles explained. "He can't. Derek's not that kind of person; he doesn't have it in him to do that to someone, even if that someone is deserving."

Peter raised one eyebrow. "And you do? You do realize you would have to then become the Beast, torturing souls for the rest of your life?"

Closing his eyes and lowering his head, Stiles took a shaky breath and whispered, "I know. I can do that. My alternative is sitting in Heaven for the rest of my life watching everyone else live. And watching Derek be miserable. I can't do that."

Peter eyed him curiously for a few moments in deep thought.

"Interestingly enough, I don't believe that you are simply taking advantage of my nephew's situation to make something of yourself. So what's the real reason? Why do you want this so badly?"

Stiles' eyes drifted up and locked with Peter's. He felt vulnerable. Open. Like a book written in Peter's tongue. He saw the moment the demon realized, saw his eyes widen slightly and then narrow into devious slits.

"Oh, I see. You can't bare to see Derek live a life of pain and unhappiness because it would kill you on the inside. It would tear you apart to have to watch him fall into hate with himself, day after day. You can't bare to see such destruction fall upon the man you love."

Stiles shut his stinging eyes and felt tears falling down his cheeks, but he nodded, because it was true.

"Hmm. Now Stiles, while this is very touching and noble of you, what do I get out of it?"

Startled by the sudden shift in conversation, Stiles opened and closed his mouth a few times, trying to come up with a response.

Seeing the boy's struggle and only feeling slightly amused by it, Peter lifted a hand that had Stiles' mouth snapping shut.

The demon sighed. "You have nothing of value for me, Stiles. We both know that. Now, I don't do this often, mind you, but I am going to give you what you want. Not out of the goodness of my heart, or as a favor. But as an investment. I know that Derek will not be able to stand under the weight of his own guilt as the Beast. He'd buckle within a decade. _You,_ on the other hand… I see something in you capable of such a fate. Capable of causing pain and suffering. I expect you to have no performance issues as the Beast of Hell. If you prove unable to stand up to the task, I will switch you back. That is my only condition."

Stiles took a moment to reel in everything he was feeling- the fear of his life to come, the relief of saving Derek from that horrible fate, the hope that everything would turn out okay. He pushed it all back and stuck out his hand.

Peter rolled his eyes. "I think we both know that's not how it works." He grasped Stiles' outstretched hand and yanked him closer, smirking at the nervousness evident in the boy's eyes.

"Just close your eyes. It'll be over quickly, I promise."

Stiles nodded and closed his eyes, holding himself stiff as a board.

Before sealing the deal, Peter asked, "Are you sure you want to do this?"

Stiles nodded.

Smiling to himself, Peter whispered into Stiles' ear, "Thank you for caring for him."

Then he tilted his head and pressed his lips against the angel's, revelling in the heady feeling of a deal being solidified and the energy flowing between them. When he pulled away, Stiles' breathing was heavy, as he no doubt felt the change prepping inside his body, waiting to consume him with it.

Peter placed a hand on the boy's shoulder and told him, "The change will take place the next time you are both asleep. Good luck, Stiles."

And with that, he was gone.

Stiles collapsed to the ground, not having the strength to hold himself up any longer. He let the final tears escape from his eyes, but also finally let himself smile, because Derek was going to be okay.

Derek would be okay. That was all that mattered.

 _ **Far from here, with more room to fly**_

 _ **Just leave me your stardust to remember you by**_

Stiles took the next twenty minutes to collect himself and walk back to the place where Isaac dropped him off. By the time he was there, he had pulled himself together enough that Isaac couldn't tell anything was seriously off and they flew back to the clouds with little conversation.

Upon entering his bedroom, Stiles saw Derek still laying in his bed, but he was slowly coming to.

Stiles let out a nervous breath and crossed the room.

"Hey, Derek," he said, sitting down on the edge of the bed and running a light hand over the boy's shoulder. "You feeling any better?"

Derek blinked groggily and sluggishly sat up. His hair was mussed and his eyes were puffy, but he looked quite a bit better than he had before.

Shrugging, he eyed Stiles curiously. "Where did you go? I woke up a little while ago and you weren't here."

 _Dammit_ thought Stiles. He had hoped to put off this conversation for at least a few hours. But as it seemed, fate didn't want to give him a single moment of calm.

Sticks cleared his throat and shifted to face Derek more directly. "Der, I need you to trust me, okay? Do you trust me?"

Without any hesitation, Derek nodded his head, even if he had a frown on his face. "Of course I trust you…" When Stiles didn't say anything, Derek hesitantly asked, "Stiles… what did you do?"

"Derek, I… shit, I have no idea how to tell you this."

"Then just tell me. It can't be that bad, right?" Derek prompted, scooting closer to Stiles and placing a hand on his arm.

The nervous boy took a deep, shaky breath and nodded. "Yeah, yeah you're right. I should just tell you." Stiles cleared his throat and looked up to meet Derek's eyes.

"I met with Peter."

Derek's eyes widened in surprise and- God, that wasn't even the important part- he looked so much like Peter in that moment, and Stiles' mind was immediately taken back to the meeting less than an hour ago, how vulnerable and open he had felt with Peter's eyes boring into them like they had, how Derek's stare never made him feel like that- well, not in the same way, anyhow. How Derek made him feel vulnerable and open in the best possible way, made him feel safe and free to expose himself in a way he just couldn't with anyone else, not his dad, not Scott, and certainly not Peter.

He was going to need to focus on that feeling of trust to get through this.

"I made a deal. And I'm sure if you don't want it we could call it off, but I just want you to listen, okay? Because this is going to sound absolutely insane and I have no idea how anyone is going to react, but I felt like I had to do it, and I just want you to really think about it. Okay? Promise me you won't freak out or anything?"

"Stiles, all you're doing right now is freaking me out! Just tell me what you did!"

Stiles jumped to his feet with a loud grunt of frustration. "I went and made a deal with Peter so the next time we're both asleep I'm going to become a demon and you're going to become an angel so you won't have to be the Beast and I will instead!"

The silence that followed Stiles' outburst was deafening. Derek's eyes were as wide as saucers and he wasn't breathing.

Stiles had felt so positive in the moment that making that deal was the best thing to do. It had seemed like the _only_ thing to do.

Now though… with the way Derek was staring at him in such shock…

Stiles felt like maybe he had fucked up.

"I'm… no, okay I'm not sorry, but I should have asked you about it first. I should have talked to you and gotten permission and I'm sorry for that, but… I can't bring myself to be sorry for doing it. Because I know how much that life would have destroyed you. It would've killed you Derek, and I couldn't just sit back and watch that happen. You deserve so much more than that, and it's not like I was throwing away this grand, promising life or anything, anyway. I figured… if I could pull something good out of my dead-end life, it may as well be for my best friend. You… you were meant to do something good, _really good_ with your life. You were meant to help people. Or, at least have the chance."

There were tears spilling over Derek's eyelids, running down his cheeks, but still he stayed silent, staring at Stiles with shocked, confused, awe-filled eyes.

Stiles had no fucking clue what that meant, and it was only adding to his desperation and anxiety.

Starting back towards Derek, he began, "Derek, please, I need you to-"

Derek lifted a halting hand, looking down at his lap.

"Just…" he whispered, voice sounding absolutely wrecked, "Just give me a minute."

Feeling frightened tears start to fill his own eyes, Stiles nodded and backed up a few steps. He ended up on the opposite side of the room, facing the wall and squeezing his eyes shut so tightly he saw stars. He tried to focus his attention on them, or else he would succumb to the worried craze he could feel creeping up on him.

It took almost ten minutes for Derek to finally pull himself from his daze, but when he did, he raised himself on shaky legs and slowly made his way over to where Stiles was standing, hunched over himself.

His hand crept up to Stiles' shoulder, then up to his neck and finally the back of his head. His other hand went to cup Stiles' cheek, lifting the angel's face and wiping the wetness away.

When Stiles opened his eyes, he saw that the expression on Derek's face had changed to one of relief and happiness, though still tinged with fear and disbelief.

Then he was being pulled into a hug so tight and intense, it stole the air from his lungs. Stiles let out a gasp of air he hadn't realized was making him lightheaded from being kept in so long, sagging into the embrace with dizzying relief.

Derek didn't hate him.

 _Derek didn't hate him._

That realization alone was enough to send Stiles spiraling back into a nebula of emotions, though this time they were much brighter than before.

"You're not mad?" he had to ask.

Derek huffed out a half amused, half exasperated breath against Stiles' neck, tightening his grip almost painfully.

"Of course I'm fucking mad, you idiot. You went and made a deal with my uncle without telling me while I was asleep," he grumbled, lips pushing against Stiles' skin with every word. Derek pulled back from the hold just enough to rest his forehead on Stiles', locking their gazes.

"But you're right. I couldn't do it. But… Stiles…" he trailed off, voice gone grim and mouth turned down again. "I don't want you to… How will you-"

"No," Stiles firmly cut him off. "Don't worry about me. I'll be fine. Someone has to do it, and it's definitely not going to be you. I'll be fine."

"But-"

"And you know what else?" Stiles interrupted again. "You'll have wings. You'll get to fly, Derek. You can come visit me anytime you want, and I'll be able to shadow travel sometimes to come see you, so we'll get to hang out like we used to."

Derek's eyes grew wide with the wondrous possibility and it was honestly one of the most beautiful things Stiles had ever seen.

"Nothing about this is a mistake, I can feel it."

"Okay. I trust you."

Apparently that was all Stiles needed to hear, because the next moment he was dragging Derek back over to the bed and seating them both down atop of it.

"So Peter said it would happen the next time we're both asleep. So let's just.. do it sooner rather than later. What do you say?"

Smiling shyly, Derek nodded and moved further up the bed. But before laying down, he gazed back at Stiles with his brows furrowed.

"How did you decide this so quickly?"

"It was an easy choice," Stiles admitted, corner of his mouth turning up at Derek.

"Why?"

"Why what?"

"Why was it an easy choice."

Instead of answering, Stiles mustered up all of his nerves and cautions, mushing them together and throwing them to the wind.

Then he leaned forward on his hands and knees and kissed Derek.

And Derek kissed him back.

He did more than just kiss back, actually; he tugged Stiles forward until he was straddling Derek's thighs. Then his hands crawled up Stiles' back until they were brushing against the bases of his crooked wings, drawing a shudder from him. When Derek moved them along the bones, caressing the broken frames and carding his fingers through the soft feathers, Stiles gasped into his mouth, dragging their bodies even closer together.

They broke apart, breathing heavily, and Derek collapsed into Stiles' broad chest, continuing his ministrations with the wings, reducing Stiles to incoherent mumbling and sporadic shudders.

No one had touched his wings since the… incident. They were more sensitive than he could remember them ever being.

Maybe it was just Derek.

Derek, who was currently trying to say something into Stiles' collarbone.

"Wha- What was that?" Stiles managed through his uneven breathing.

Derek's hands stilled where they were buried in the feathers at the tips of the wings, drawing a whine from Stiles.

Drawing his head back, Derek's eyes sought out Stiles', and when they made contact, he smiled and whispered, easily, "I love you."

The joyful laugh that escaped Stiles' mouth was caught by Derek as he reached up for another kiss. Their lips were constantly moving, breaking away, reattaching, finding new angles, all the while smiling and caressing one another wherever they could reach.

Later, when they had finally laid down, Stiles whispered against Derek's now ever present lips, "I love you, too."

 _ **If you be my boat, I'll be your sea**_

 _ **A depth of pure blue just to probe curiosity**_

 _ **Ebbing and flowing and pushed by a breeze**_

The next day wasn't easy. There was a lot of yelling and a lot of confusion and a lot of emotions coming from both Stiles' father and the Hales. Stiles couldn't imagine what the reactions of everybody else were going to be.

But the look of pure joy on Derek's face as he woke up to a pair of white, fluffy, strong wings was well worth it. And the sensation of Derek's arms around him, carrying him through the clouds on that light, cool, and humid morning made him feel free in a way he hadn't in years.

Things would be difficult. Stiles would eventually have to start training to become the Beast- hitting and slicing and burning the souls of the damned. But he could do it. Peter was right; he was capable.

Derek would probably become a Guardian, protecting the humans of some town or village somewhere on Earth. He would help keep people safe, and it would make him so happy, and that would make Stiles happy.

Remembering that, and watching the love shine through Derek's smile as they soared through the air, was more than enough to get him through the hard parts.

And he knew it would be enough to get him through them for the rest of his life.

 _ **I live to make you free**_

 _ **I live to make you free**_


End file.
